Role of MR and CT in the paranasal sinuses

This article discusses the benefits and drawbacks of MR imaging and computed tomography as they relate to sinus disease.     

Head and neck malignancy: is PET/CT more accurate than PET or CT alone?

PURPOSE: To prospectively determine whether combined positron emission tomography (PET) and computed tomography (CT) is more accurate than either PET or CT alone in depicting malignant lesions in the head and neck. MATERIALS AND METHODS: Study was approved by the institutional review board, and patient informed consent was waived. Sixty-five consecutive patients (42 men, 23 women; age range, 43-83 years) known to have or suspected of having head and neck cancer were examined with combined PET/CT. CT was performed with intravenous administration of a contrast agent, and the CT data were used for attenuation correction. Each examination was interpreted in three ways: PET images in the absence of CT data, CT images in the absence of PET data, and fused PET/CT images. Probability of malignancy of each lesion was assigned a score by using a five-point scale. Receiver operating characteristic (ROC) analyses were performed by using biopsy, imaging, or clinical follow-up as the reference standard. The minimum follow-up was 6 months (range, 6-12 months). The results were additionally analyzed to assess the degree of radiologist confidence. RESULTS: Follow-up was available for 64 (98%) of 65 patients. ROC analyses demonstrated that PET/CT is significantly superior to PET or CT alone for depiction of malignancy in the head and neck (P < .05). In this series, PET/CT had a sensitivity of 98%, a specificity of 92%, and an accuracy of 94%. Radiologist confidence was substantially higher with the combined modality. CONCLUSION: Combined PET/CT is more accurate than PET or CT alone for the depiction of malignancy in the head and neck. Radiologist confidence is improved with the combined modality.     

Cricoarytenoid rheumatoid arthritis: an important consideration in aggressive lesions of the larynx

The most frequent cause of an aggressive mass in the larynx is squamous cell carcinoma (SCC). Rheumatoid arthritis is known to affect the larynx but does not usually produce an aggressive mass. We present a case of rheumatoid arthritis in a 63-year-old woman who presented with acute upper airway obstruction. On CT scans, an erosive mass on the right cricoid cartilage with significant destruction of the surrounding structures was presumed to be an aggressive SCC. Surgical biopsies revealed rheumatoid arthritis of the cricoarytenoid joint. When a patient with rheumatoid arthritis presents with a mass in the larynx, cricoarytenoid rheumatoid arthritis should be ruled out even in the face of an aggressive lesion appearance at CT.     

Interleukin-6 alters the cellular responsiveness to clopidogrel, irinotecan, and Oseltamivir by suppressing the expression of Carboxylesterases HCE1 and HCE2

Carboxylesterases constitute a class of enzymes that play important roles in the hydrolytic metabolism of drugs and other xenobiotics, patients with liver conditions such as cirrhosis show increased secretion of proinflammatory cytokines [e. g., interleukin-6 （IL- 6）] and decreased capacity of hydrolysis. In this sfudy, we provide a molecular explanation linking cytokine secretion directly to the decreased capacity of hydrolytic biotransformation. In both primary hepatocytes and HepG2 cells, treatment with IL-6 decreased the expression of human carboxylesterases HCE1 and HCE2 by as much as 60%. The decreased expression occurred at both mRNA and protein levels, and it was confirmed .by enzymatic assay. In cotransfection experiments, both HCE1 and HCE2 promoters were significantly repressed, and the repression was comparable with the decrease in HCE1 and HCE2 mRNA, suggesting that transrepression is responsible for the suppressed expression. In addition, pretreatment with IL-6 altered the cellular responsiveness in an opposite manner of overexpression of HCE1 and HCE2 toward various ester therapeutic agents （ e. g., clopidogrel）. Transfection of HCE1, for example, decreased the cytotoxicity induced by antithrombogenic agent clopidogrel, whereas pretreatment with IL-6 increased the cytotoxicity. Such a reversal was observed with other ester drugs, including anticancer agent irinotecan and anti-influenza agent oseltamivir. The altered cellular responsiveness was observed when drugs were assayed at sub-and low-micromolar concentrations, suggesting that suppressed expression of carboxylesterases by IL-6 has profound pharmacological consequences, particularly with those that are hvdrolvzed in an isoform-specific manner.     

Ethylnitrosourea-induced transplacental carcinogenesis in the mouse: tumor response, DNA binding, and adduct formation

We have confirmed previous results which suggest that transplacental exposure of fetal mice to carcinogens does not cause an increase in tumor incidence as they mature unless treatment occurs after midorganogenesis. In C3HeB/FeJ mice we found a negligible increase in tumor incidence and multiplicity following transplacental exposure to the direct-acting carcinogen ethylnitrosourea (ENU) on gestation day 10, but significant increases in lung and liver tumor incidence following exposure on days 13 or 15 or in adults. To explore the possibility that this observed difference is due to differences in the biodistribution of the carcinogen or its interaction with cellular macromolecules, the level of covalent binding between ENU and fetal and maternal DNA following an i.p. injection of a dose of 50 mg/kg of tritium-labeled ENU was measured 30 min after its injection into pregnant females on days 10, 13, and 15 of gestation. The DNA from fetal and maternal lung, liver, and brain was isolated and the amount of covalent binding estimated from the dpm/mg DNA recovered. Samples of DNA were hydrolyzed and chromatographed to determine that the bound tritium was associated with ENU-DNA adducts and not as a product of DNA synthesis. The level of binding of ENU to fetal DNA was equivalent at all gestation days studied but was significantly less than maternal tissues. Binding to the DNA of maternal liver was 4-fold greater than to fetal DNA while maternal lung and brain DNA were bound at intermediate levels. We conclude that the lack of carcinogenic response to ENU documented here, in fetal mice exposed early in gestation (day 10), is not due to differences in ENU binding to fetal DNA during development.     

Preliminary in vitro evaluation of an adjunctive therapy for extremity wound infection reduction: Rapidly resorbing local antibiotic delivery

Despite the continuing advances in treatment of open fractures and musculoskeletal wounds, infection remains a serious complication. Current treatments to prevent infection utilize surgical debridement and irrigation, and high doses of systemic antimicrobial therapy. The aim of this work was to evaluate, in vitro, the potential of a fast‐resorbing calcium sulfate pellet loaded with an antibiotic. The pellet could be used as an adjunctive therapy at the time of debridement and irrigation to reduce bacterial wound contamination. Small pellets containing a binder and calcium sulfate were engineered to resorb rapidly (within 24 h) and deliver high local doses of antibiotic (amikacin, gentamicin, or vancomycin) to the wound site while minimizing systemic effects. Results from dissolution, elution, and biological activity tests against P. aeruginosa and S. aureus were used to compare the performance of antibiotic‐loaded, rapidly resorbing calcium sulfate pellets to antibiotic‐loaded crushed conventional calcium sulfate pellets. Antibiotic‐loaded rapidly resorbing pellets dissolved in vitro in deionized water in 12–16 h and released therapeutic antibiotic levels in phosphate buffered saline that were above the minimal inhibitory concentration for P. aeruginosa and S. aureus, completely inhibiting the growth of these bacteria for the life of the pellet. Crushed conventional calcium sulfate pellets dissolved over 4–6 days, but the eluates only contained sufficient antibiotic to inhibit growth for the first 4 h. These data indicate that fast‐resorbing pellets can release antibiotics rapidly and at therapeutic levels. Adjunctive therapy with fast‐acting pellets is promising and warrants further in vivo studies. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 903–908, 2009     

7-溴乙氧苯四氢巴马汀对离体豚鼠工作心脏的作用

用Tris-丙酮酸钠液灌流离体豚鼠工作心脏,记录左室压的导管从左房灌流管插入,可使心脏有效工作时间达70min。用Tris-丙酮酸钠液加0.5%的氟碳液能使有效工作时间延长至90min。7-溴乙氧苯四氢巴马汀(7-bromoethyoxybenzene tetrahydropalmatine,EBP)及哌唑嗪0.1μmol/L对工作心脏各项指标均无显著影响。甲氧胺1μmol/L,多巴胺1μmol/L对LVP,ABF,T-CO等指标均有明显的药理作用。EBP 10μmol/L能对抗甲氧胺、多巴胺对上述指标的影响。     

Early postoperative hyperglycaemia is not a risk factor for infectious complications and prolonged in-hospital stay in patients undergoing oesophagectomy: a retrospective analysis of a prospective trial

Introduction  

Treating hyperglycaemia in hospitalized patients has proven to be beneficial, particularly in those with obstructive vascular disease. In a cohort of patients undergoing resection for oesophageal carcinoma (a group of patients with severe surgical stress but a low prevalence of vascular disease), we investigated whether early postoperative hyperglycaemia is associated with increased incidence of infectious complications and prolonged in-hospital stay.